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  • Speaker Protection Circuit-2

  • Created: Dec 17, 2016

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R1 & R2 Use higher resistance for higher Wattage ......56K {250-1000 Watts}.....8.2k {10-200 Watts}..


This circuit prevents the speaker from damage by not feeding an overvoltage supply through it. In addition, the frequency response of the circuit is way better than the other circuits available. The device uses power amplifiers, full bridge rectifiers and NPN transistors to effectively support the speakers.

As shown in the circuit, the signal from the speakers enter through resistors R1 and R2 into the protection speakers section. To reduce the signal strength, the capacitor C1 serves to bypass this signal to ground. However, if the dc voltage either positive or negative is passed through the bridge diode circuit, this sets the voltage input either positive or negative to the positive voltage which drives the base of transistor Q1. When transistor Q1 is working, it will make the collector voltage to drop and the bias voltage at base of transistor Q2 will also drop, making transistors Q2 and Q3 to deactivate. No current will pass through the relay RY1 where the signal through the power amplifier is cut off. Therefore,the speakers are safe from overrating power.

Speaker protection circuit is simple yet practical to use. It may be used by electronic enthusiasts to protect their speakers from damage. It is another type of overvoltage protection where the concept can also be used not only to speakers but to any other devices that need extra aid.



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